The present invention relates to a pneumatic tire having improved turnability during high speed running. More specifically, the invention relates to a pneumatic tire which is suitably used for racing.
With heightened vehicular performance in recent years, further improvement has been demanded for tire turnability during high speed running. Specifically, an excessive lateral force is applied to an outer side of a turning tire when a vehicle is turned during high speed running. A side section and a bead section outside the vehicle fall to the inner side of the tire. Consequently, limitation is put on turnability.
Conventionally, efforts have been made to improve turnability during high speed running by preventing falling of the bead section during turning. For example, a bead section structure was presented (Japanese Unexamined Patent Laid-Open No. 6 (1994)-227216), which uses a bead core made of single strand steel, a rubber stock having hardness set in a range of 80.degree. to 98.degree. of JIS-A hardness and arranged in a bead toe section, and a chafer composed of a non-metallic fiber cord and arranged on an outer surface of the rubber stock.
However, the foregoing bead section structure has been unable to satisfy a recent demand for higher speed driving. For example, it is impossible to secure driving stability when a vehicle is run on a corner of a 100 m radius at a high speed of 200 km/h.